Using the edge loop tool

I’m reading the modeling techniques thread and it looks really helpful. I just can’t figure out how to make the edgeloop tool work. I’ve got ctrl+r down, but when the line appears I don’t know what to do. Please advise.

When the line first appears (after Ctrl+R), you use that to say which faces to cut. When you know which ones you want, left click. Then you will get a different line. You can move it left and right. That shows where the verts will be cut into. When you have it where you like, left click again to cut the faces.